The spectral lines of a star indicate ionized helium is prominent, yet the star appears
orange in color. Explain the problem with this and offer an explanation.
A property common to active galaxies is that their energy is primarily ________.
How does Hubble’s law relate cosmological redshift to distance?
The apparent annual path the Sun takes through the sky is called the ________.
Arcturus, the brightest star of spring skies, is spectral type K, so to us it appears
________ in color.
The ________ hypothesis is now the most popular to explain the Moon’s origin.
Compare the Copernican principle with the assumptions of mediocrity.
The most luminous quasars can give off ________ times more light that our own
Galaxy.
What are the minimum and maximum values for right ascension in the sky?
What is the relationship between a star’s mass and its lifetime?
In what way is the formation of a galaxy from a cloud the opposite of stellar formation?
Helium production ceased when the universe was about ________ minutes old, and did
not resume until the first generation of stars formed.
Herbig-Haro objects at opposite ends of bi-polar jets can span a ________ across.
List the six main regions of the Earth, in order, starting from the center.
Stellar masses are determined by observing ________ stars.
The ________ planets are large bodies in the outer solar system with compositions like
the Sun’s.
Define the celestial sphere.